Improvement in saw-sharpening machines



T. M. CHAPMAN. Saw-Sharpening Machines.`

NO. 144,383. Y Patented No`v.1l, 1873.

` saw does not interfere with the clamp.

UNITED STATES 'PATENT OFFIOH THOMAs M. CHAPMAN, OF OLD TOWN, MAINE.

IMPROVEMENT IN SAW-SHARPENING MACHINES.

Specification forming part of Lettexs Patent No. 144,383, dated Ntvemberll, 1873; application led June 6, i873. l

To all whom it 'may concern:

Be it known that 1, THOMAS M. CHAPMAN, of Old Town, in the county ofPenobscot and State of Maine, have invented certain new and usefulImprovements in Saw-Clamps; and I do hereby declare that the followingis a full, clear, and exact description thereof, that will enable othersskilled in the art to which it appertains to make and use the same,reference being had to the accompanying drawings and to the letters ofreference marked thereon, which form a part of this specification, inwhich- Figure l shows a side view, and Fig. 2 a front eleva-tion, of myinvention.

Same letters show like parts.

Myinvention consists of a clamp for hold ing saws While being led, andalso of certain devices for feeding the saw to the le Without unclamping it. It is capable of holding saws of all descriptions, and possessesmany advantages over ordinary clamps,which are inconvenient in manyrespects, having to be loosened each time the saw is moved forward, andbeing but poorly adapted to holding saws having projecting collars.

Referring to the drawing, a shows a base or platform, to which isattached a standard, b, of convenient height, the upper portion of whichforms one side or jaw, c, of the clamp. To this standard, at one side ofand rising above the jaw o, is a projection or horn, d, having a holetherein, through which passes one end of an arm, e, so constructed as toturn in said horn in a vertical plane, and also having a longitudinalmotion therein. To the other end of this arm, which is curved downward,is attached the movable jaw f of the clamp. The manner of attachment ofthe arm e to the horn d enables the jaw f to be swung vertically up whena saw is to be inserted in the clamp. This takes it entirely out of theway. The saw being placed in position, it is swung downward, holding itfrom the top instead of from the bottom or center, in consequence ofwhich the collar (if any) upon the The jaw f is set up to the jaw c bymeans of a thumb-screw, y, upon the end of the arm c,

projection, which engages and holds it when y raised or clamped.

The construction and operation of the vertically-swin ging jaw will beunderstood by referring to the drawing. In Fig. l it is shown i raised,preparatory to inserting the saw, while Fig. 2 shows it down, as whenthe saw is clamped.

In order to enable the saw to be fed forward to present successive teethto the action of the file, I provide both jaws c and f with rollers,between which the saw is held. The rollers h h in the stationary jaw care revolved when required by appropriate machinery giving motion to thesaw, while the rollers t' i' t' in the movable jaw f serve to lessen thefriction.

I will explain the method by which I propose to give revolution to therolls h. I extend their shafts downward through the standard b to abearing, w, and attach to their ends gears j 7c. Between and meshinginto them I place a third gear, l, upon an upright shaft, m, which shafthas also upon it a bevelgear, n, meshing into a second bevel-gear upon ahorizontal shaft, p. Upon the other end of this shaft p is a treadle, q,moving loosely thereon, but actuating the shaft p in one direction bymeans of a pawl, r, meshing into a ratchet, s, upon said shaft. When thesaw is to be fed forward the treadle is operated, transmitting themotion through the intermediate gears and shafting to the rolls h h,which feed the saw forward, as required.

The standard b and all its attachments are constructed so as to turnupon a vertical pivot, as common. gears n o permits this to be donewithout interfering with their operation, the gear o turning around thegear a as the standard moves. A clamp, is provided, adjustableperpendicularly in a slot, t, of the standard b, enabling the saw orsaw-rest to be secured at different heights on the standard. It alsoaffords an The arrangement of the beveladjustable center, upon whichcircular saws with their shafts and gears Zn and shaftm,

bevel-gear, and shaft p, connecting them With the loose treadleq,whereby motion is transmitted to said rollers, al1 arranged as hereinset forth, for the purposes described.

3. The combination ofthe feeding devices with the swiveling standard, asdesoribed.

In testimony that I claim the foregoing I have hereunto set my hand this3d day of June, 1873.

THOMAS M. CHAPMAN. Witnesses:

J. B. BASS,

WM. FRANKLIN SEAVEY.

